gasket thickness

[Nate408]

Im putting a je 10.5:1 stock bore piston and stage2 hotcam in my 400ex this weekend. im using cometic .043 gasket p/n c7279. using the comp calc on rosspistons.com the comp ration will actually be 9.74:1 with .043 gasket and stock base. if change to a .020 head gasket comp will be 10.4:1. Does this sound right? Im leary of running no base gasket. what is the stock xr400 head gasket thickness? Please help
thanks,
Nate

[cals400ex]

i run the thin cosmetic head with no base gasket on my 11:1 426. i run hondabond on the base. we have now done this in 2 406's, a 416, and my 426. i can't tell you the exact gasket thickness but i can tell you this has worked out well for us. call C&D, they should be able to answer further questions.

[BLEEDRED]

I too run hondabond on the base with no problems.

[Colby@C&DRacing]

We have a thinner gasket kit just for this reason to raise the compression higher the the piston allows;)

[BLEEDRED]

We have a thinner gasket kit just for this reason to raise the compression higher the the piston allows

What is the thickness of the gasket and are you talking head gasket, base gasket or both? What is the material of the gaskets and what it the cost?

[Nate408]

C&D,
what is the p/n and cost?
Thanks,
Nate

[Colby@C&DRacing]

We have std thinkness gaskets made and we also have a thinner kit. The thin kit is a thinner base and head gasket. the base is fiber and the head is a steel flex gasket. The kit also comes with steel cam chain tensioner and four orings for the valve covers tappits. We have these kits custom cut from cometic and the cost is $40 per kit

[Nate408]

Do you have this in stock? Need by this weekend

im guessing hondabond is a brown "peanut butter" type substance also known in the marine world as perfect seal?

Jesse

[Silverfox@C&DRacing]

Originally posted by Nate408
Do you have this in stock? Need by this weekend

we stock these gaskets if you need by tomorrow we would have to overnight it..

[BLEEDRED]

We have std thinkness gaskets made and we also have a thinner kit. The thin kit is a thinner base and head gasket.

Come on, we all know how important gasket thickness is in determining our compression ratio. You can't just say "thinner" when we all know a few thousandths of and inch can make or break the whole project. Please post the thickness of both base and head gaskets.

[400exrider707]

Originally posted by BLEEDRED
Come on, we all know how important gasket thickness is in determining our compression ratio. You can't just say "thinner" when we all know a few thousandths of and inch can make or break the whole project. Please post the thickness of both base and head gaskets.

Also how much $ for the "thinner kit"

[Nate408]

C&D
Were you able to get those gaskets shipped?
really appreciate the fast service.
Thanks again,
Nate

[BLEEDRED]

So Nate408, what was the thickness of the gaskets? I mean, how do you know you are going to be running the right compression? Just saying "thinner" doesn't cut it for me.

[Nate408]

When I talked to c&d yesterday they said the thinner gaskets should compute to 10.8:1 with stock bore piston. or what was it 10.6:1 anyways ill sure mic the thickness of the gaskets and check on the compression calculator. I dont remember the exact thickness when talking with on the phone. but i should know by sat evening or sunday and ill post the results. Also does anyone know if these are one time use gaskets only? the reason i ask is ill will mock the motor together, torque head, to check clearance, piston valve etc. I know some gaskets once torqued are not supposed to be used again.
Nate 408

[Nate408]

Hey,
u guys give me your opinions on how this will run compared to stock. 10.5:1 stock bore Je, stage 2 hotcam, jetted carb with k&n, and hmf exhaust. stock gearing.
Thanks,
nate408

[BLEEDRED]

When I talked to c&d yesterday they said the thinner gaskets should compute to 10.8:1 with stock bore piston. or what was it 10.6:1 anyways ill sure mic the thickness of the gaskets and check on the compression calculator.

Still not good enough for me if they can't even tell you the gasket thickness, or post it in this forum. But who am I to say, I'm just another annoying member asking questions and trying to get people to back up what they are saying...words like "thinner" and "should" just aren't enough for me when building a high tolerence engine.

Good idea to throw a set of calipers on them and check everything in the CR calc. Also a good idea to mock the engine and check everything. Sounds like the head gasket is a flex steel gasket which doesn't compress so you could just set up without it and add the gasket thickness to your clearence. I DON'T know if you can torque them more than once. The base gasket sounds like a fiber gasket and once you torque it you wouldn't have to remove it to check the clearance.

Good luck!!!!!!!! Remember to check the end gap on your rings and set your valve lash. You will also want to go back to check the valve lash again after initial break in.

[Nate408]

Bleedred,
Im will def check everything possible, also my dad will be helping and is a machinist of more than 30 years. His help is invaluable. So how do like your stage 2? i was going to use stage 1 but most everyone just going to the stage2.

[BLEEDRED]

Well I don't really know any differnt because I have never had a stage one, but I am happy with my stage two. My 440 is a torque monster which makes the trails pretty fun plus the stage two seems to have pretty good mid and top end. I actually have it torn down right now to install a HD timing chain and HD head studs and also to replace some of the head cover bolts. So I haven't actually run it with the sparks pipe yet. I'm hoping the sparks full system will uncork the power of the big bore as I was just running with the stock header and a WB slip-on before.

Not sure if you have torn your engine apart before, but a word of caution when putting the head cover back on. The 8mm bolts are weak and I think there might have been a misprint in the Clymer. Not sure what they recommended for torque, but I would be really careful and use a 1/4" drive to install the 8mm bolts and be sure to dip the threads in oil. I broke the three long 8mm bolts that thread into the jug. One broke and two stripped. That caused my head gasket to blow out around the timing chain. So I am coming back with heli colis and HD studs to be safe.

[cheatin mother]

Don,t hold me to this but .027 comes to mind. I measured when i did mine about a year ago but didn,t log anything down. Hope this helps !